i have to admit that i wondered this very thing myself.. adding an airstone to soil for added oxygen.. don't forget that people used to laugh at the guy who said why not grow veggies not in soil, but just using water instead, ie hydroponics... but look who is laughing now.. imagine all of the nahsayers on this guys riu of the day.. i am sure that people also said i have been growing in soil for 100 years, and i have forgotten more than you will ever know as well.. but this guy persisted in a thought that he had, and look where we are today..
no idea is stupid... this is science my brother.. you have an idea, you test it out.. do expirements with it, let others try it out.. let idea be proved or disproved.. and idea that has been disproved is never stupid, it is just an idea that has been disproved.. try something else..
and yes, airstones in your water/ nutes is a very good thing.. the extra oxygen it much appreciated by your babies..
best of luck with your grow, and dont let others persuade you from trying new and different things just because you idea sounds a little different to the masses..